Earthquake · reviewed by a seismologist
M 2.5md
Earthquake near Eureka, MO
No earthquake was likely felt in Eureka in the 24 hours to 5:12 am CST (11:12 UTC). The last one was M 3.5, 232 km (144 mi) E, at 2:05 am CDT on 29 June 2026, estimated intensity II (weak) in town; 392 felt reports to USGS. Every earthquake near Eureka
This page: a magnitude 2.5 earthquake was recorded 3 km (2 mi) east-southeast of Eureka, MO, at 3:38 am CDT on 20 April 2021 (08:38 UTC), 19 km deep. 474 people have reported feeling it to USGS.
USGS: 2 km ESE of Eureka, Missouri
35 km (22 mi) WSW of St. Louis, MO · 33 km (20 mi) S of St. Peters, MO
- When
- 3:38 am CDT on 20 April 2021 ()
- Where
- 3 km (2 mi) east-southeast of Eureka, MO · earthquakes near Eureka
- Missouri today
- every earthquake in Missouri in the last 24 hours
- Magnitude
- M 2.5 (md)
- Depth
- 19 km below the surface
- Felt
- 474 reports · strongest reported intensity V
- Nearest
- St. Louis County, 22 km NE
- Nearest mapped fault
- St. Louis-Cape Girardeau liquefaction features, under 1 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1435 days ago
Earthquake alerts for Eureka, MO
Get a notification in this browser when USGS records an earthquake near Eureka, MO. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 40 km (25 mi) from the epicentre. In Eureka, 3 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Earthquakes near other towns within 30 km: Byrnes Mill, High Ridge, Murphy, LaBarque Creek, Ellisville, Wildwood.
How big was it?
This earthquake released about 150 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 100,000× the energy of this one
- Magna, Utah 2020 M 5.7 72,000× the energy of this one
- Around the size people start to feel M 3.0 6.5× the energy of this one
- This earthquake M 2.5 about 150 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 38.4902, -90.6028. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| St. Louis County, MO | 22 km (13 mi) | NE | earthquakes near St. Louis County |
| Jefferson County, MO | 26 km (16 mi) | SSE | earthquakes near Jefferson County |
| St. Charles County, MO | 33 km (20 mi) | N | earthquakes near St. Charles County |
| St. Louis city, MO | 35 km (22 mi) | ENE | earthquakes near St. Louis city |
| Franklin County, MO | 42 km (26 mi) | WSW | earthquakes near Franklin County |
| Monroe County, IL | 44 km (27 mi) | ESE | earthquakes near Monroe County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
8 earthquakes have been recorded within 50 km since this one.
- 2.0 6 km SSW of Valmeyer, Illinois
- 2.4 3 km ESE of Fenton, Missouri
- 1.7 3 km WNW of Olympian Village, Missouri
- 2.3 4 km S of Valmeyer, Illinois
- 2.3 4 km E of Herculaneum, Missouri
- 2.6 1 km S of Old Monroe, Missouri
- 2.5 eastern Missouri
- 2.8 1 km SSW of Peerless Park, Missouri
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.